Pulverizing mill



D. V. SHERBAN.

PULVERIZING MILL.

APPLICATION FILED DEC-23.1921.

mzmsa I H HQ n. V. SHERBAN.-.

PULVERlZlNG MILL. APPLICATION FILED DEC-23,4921.

PatentedAug. 29, 1922;

2 SHEETS-SHEET 2.

,"ffazw DANIEL V. SHERBAN, 0F CANTON, OHIO.

PULVEBIZING MILL.

Specification of Letters Patent.

HElSSUED Patented Aug. 29, 1922.

Application filed December 23, 1921. Serial 10. 524,524.

To all whom it may concern:

Be itknown that I, DANIEL V. SHERBAN, acitizen of the United States, residing at Canton, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in Pulverizing Mills, of which the following is a specification.

My invention relates to improvements in machines having for their purpose the crushing or pulverizing coal or other slmilar material. It has for its object to effect the pulverization and gradation of a suitable substance, as coal, and to provide a machine for such purpose inwhich the coal is delivered into a rotatable drum and subjected therein to the crushing and pulverizing action of series of loose balls operatin upon the coal by gravity and centrlfuga action as the drum revolves.

One particular feature of novelty involved is in providing means for screening and carrying off the fine dust, as it is produced, from the interior of the drum, and for maintaining and protecting such means, together with various other features of construction and operation, as shall be more fully hereinafter described.

In the drawings,

Fig. 1 is a view in longitudinal section, partly in elevation, showing a complete apparatus as assembled; I

Fig. 2 is a cross section on line II-II of Fig. 1;

Fig. 3 is a diagrammatic view showing a rotatablegrinding barrel in cross section, showing the action of the balls within an uninterrupted area Fig. 4 is a similar view-showing the novel effect of introducing the interferlng screen; and

Fig. 5 is an enlarged sectional detail view of a portion of the central screen.

The main operative member of the crushing apparatus consists of a rotatable drum or tumbling barrel 2, the heads or ends 3-3 of which are mounted in suitable bearings 99 by means of the hollow trunnion extensions 4-4. The receiving end of the drum communicates through one of said trunnion extensions with a supply pipe 5, to which lump coal is delivered by conduit 6 leading from a hopper terminal 7 or other source of supply. The conduit 5 has a valve controlled terminal 8 at any suitable inlet point for the reception of atmospheric air.

the fuel, and

The other head 3 is similarly mounted by its trunnion 4 in the opposite bearing 9 and communicates through the said trunnion with a suction or exhaust fan 10 actuated by a suitable drivin' motor, adapted to collect the dust as pro need, and having a delivery conduit 11 leading to a furnace or other point of consumption or storage.

The interior of the drum 2 may be continuously open from end to end, or may be divided into a series of sectional compartments a, b, respectively, divided by an annular partition wall 12 extending transversely across the drum area and serving to retain the series of crushing balls 13 in place. Longitudinal strips or abutments 14 extend at intervals throughout the length of the inner circumference of the drum, in the manner of slats or ridges, and with centrifugal force, have the function and effect of partially lifting the balls and dropping them as the drum rotates in carrying out its work of crushing and grinding the coal.

Extending inwardly through the central portion of the drum near its receiving end, 1s a cylindrical screen 15 communicating with the intake end of fan 10 through the trunnion .4 of the drum. The screen may be formed of comparatively fine mesh screen so as to prevent the passage therethrough I of any particles of coal not sufficiently small to use as pulverized fuel, or may be otherwise made so as to admit to its interior only such fuel as is sufficiently fine to be utilized with an air feed column. In the drawings, the cylinder is shown as of comparatively heavy sheet ,or plate metal, extending into the suction conduit at its delivery end and open for inflow of pulverized material throughout its length clear to the opposite end. Screen 15 is supported within the trunnion 4 by extended rods 16. Cylinder 15 is provided throughout its body portion with series of longitudinally arranged slots or openings 17 comparatively narrow at their outer portions and enlarging inwardly by a widening taper, as shown. By this means, the entrance opening controls the size of prevents a tendency to clog the slots.

The supply of air is preferably controlled through an adjustably mounted air inlet.

valve 18 of easing suitably connected by rod 19- and asheave-guided cord 20 with a rheostat 21.

the path of the falling balls, as in Fig. 4.

The resulting effect is that the stream of falling balls is divided and passes downwardly at each side. Those balls which fall toward the main rising stream of balls at the ascendin side of the drum are engaged frictiona y theleby, and the result is that a small cyclonic zone X is induced with a resulting rotary path of travel, as indicated by the arrows. The effect is to greatly accelerate the grinding and pulverizing action, and this is increased by using a mass of balls of varyin size in the common interior of the drum. 'fhe balls which pass over to the other side of the screen are somewhat Spread apart and more freely distributed, and there is thus a constant tendency to improve the grinding action. A further advantage is that the constant hammering of the balls on the central screen tends to dislodge any adhering particles, thus keeping the slots 17 open and unobstructed.

The drum may be rotated in any suitable way, as b a pinion 22 engagingan annular rack 23, t e speed of rotation being suitably controlled by the driving gearing. v

The construction and operation of the invention will be readil understood and appreciated from the oregoing description. The machine is capable of continuous and successful operation in the manner intended, without liability of getting out of order, and is well adapted to perform its intended functions in continuously ulverizing the coal and delivering the pulverized fuel in continuousl uniform grade.

The mac ine may be built in different sizes to suit local requirements, or variously changed in detail construction or othermemes.

wise by the skilled mechanic, but all such changes are to be considered as within the sco e of the following claims.

hat I claim is:

1. A grinding mill consisting of a rotatable drum provided with grinding balls and a central axially arranged suction screen having a continuous uninterrupted razeiving cavity from one end to the other.

2. A grinding mill consisting of a rotatable drum provided with grinding balls, a central axially arranged suction screen having a continuous uninterrupted receiving cavity from one end to the other, means providing an extracting current therethrough, and means for introducing raw material to the drum.

3. In combination, a rotatable drum, means for introducing raw material and air to one end thereof, a central axially arranged cylindrical screen extending inwardly of the drum from the other end thereof having a continuous uninterrupted receiving cavity from one end to the other, and a suction fan and exhaust conduit communicating therewith.

4. In combination, a rotatable drum, means for introducing raw material and air to one end thereof, a centrally arranged cylindrical screen extending inwardly of the drum from the other end thereof provided with inwardly enlarging circulation openings and a continuous interior receiving cavity, and a suction fan and exhaust conduit communicating therewith.

5. In combination, a rotatable drum having terminal hollow trunnions for inlet of raw material and air and outflow of pulverized material and air, a suction fan connected with the outflow trunnion, a central axially arranged suction screen extending from the outflow trunnion inwardly of the drum towards the receiving trunnion having a continuous open interior, means for supporting the screen, and a series of grinding balls in the drum.

In testimony whereof I hereunto afiix my signature.

DANIEL v. SHERBAN. 

